Effects of thienopyridine class antiplatelets on bleeding outcomes following robot-assisted radical prostatectomy.

This study aimed to assess the effects of thienopyridine-class antiplatelet agents (including ticlopidine, clopidogrel, and prasugrel) on bleeding complications in patients who underwent robot-assisted radical prostatectomy. This cohort study used a database for robot-assisted radical prostatectomy at 23 tertiary centers nationwide between 2011 and 2022. Patients who received thienopyridines (thienopyridine group) were compared with those who received aspirin monotherapy (aspirin group). The primary outcome was the incidence of bleeding complications. High-grade complications were defined as Clavien-Dindo grade III or higher. The risks of these outcomes were evaluated using inverse probability of treatment weighted regression models. The study results demonstrated that thienopyridine therapy was associated with a higher risk of overall bleeding complications (OR: 3.62, 95%CI 1.54-8.49). The increased risks of the thienopyridine group were detected for low-grade bleeding complications (OR: 3.20, 95%CI 1.23-8.30) but not for high-grade bleeding complications (OR: 5.23, 95%CI 0.78-34.9). The increased risk of bleeding complications was not observed when thienopyridine was discontinued (OR: 2.52, 95%CI 0.83-7.70); however, it became apparent when it was continued perioperatively (OR: 4.35, 95%CI 1.14-16.61). In conclusion, thienopyridine increased the incidence of bleeding complications, particularly low-grade bleeding complications, following robot-assisted radical prostatectomy. These bleeding effects emerged when thienopyridine was continued perioperatively.

ANGPTL2-mediated epigenetic repression of MHC-I in tumor cells accelerates tumor immune evasion.

Loss or downregulation of major histocompatibility complex class I (MHC-I) contributes to tumor immune evasion. We previously demonstrated that angiopoietin-like protein 2 (ANGPTL2) promotes tumor progression using a Xp11.2 translocation renal cell carcinoma (tRCC) mouse model. However, molecular mechanisms underlying ANGPTL2 tumor-promoting activity in the tRCC model remained unclear. Here, we report that ANGPTL2 deficiency in renal tubular epithelial cells slows tumor progression in the tRCC mouse model and promotes activated CD8+ T-cell infiltration of kidney tissues. We also found that Angptl2-deficient tumor cells show enhanced interferon γ-induced expression of MHC-I and increased susceptibility to CD8+ T-cell-mediated anti-tumor immune responses. Moreover, we provide evidence that the ANGPTL2-α5ß1 integrin pathway accelerates polycomb repressive complex 2-mediated repression of MHC-I expression in tumor cells. These findings suggest that ANGPTL2 signaling in tumor cells contributes to tumor immune evasion and that suppressing that signaling in tumor cells could serve as a potential strategy to facilitate tumor elimination by T-cell-mediated anti-tumor immunity.

Sicca syndrome during ipilimumab and nivolumab therapy for metastatic renal cell carcinoma.

Introduction: Dry mouth is the main symptom of sicca syndrome, which rarely occurs as an immune-related adverse event. Here we report a case of sicca syndrome caused by immune checkpoint inhibitor treatment. Case presentation: A 70-year-old man was diagnosed with left renal cell carcinoma after radical left nephrectomy. Nine years later, computed tomography revealed a metastatic nodule in the upper left lung lobe. Subsequently, ipilimumab and nivolumab were administered for recurrent disease. After 13 weeks of treatment, xerostomia and dysgeusia were noted. Salivary gland biopsy revealed lymphocyte and plasma cell infiltration in the salivary glands. Sicca syndrome was diagnosed and pilocarpine hydrochloride was prescribed without corticosteroids, with continuation of immune checkpoint inhibitor therapy. The symptoms alleviated after 36 weeks of treatment, with shrinkage of the metastatic lesions. Conclusion: We experienced sicca syndrome caused by immune checkpoint inhibitors. Sicca syndrome improved without steroids and the immunotherapy could be continued.

Predictive value of CXCL10 for the occurrence of immune-related adverse events in patient with renal cell carcinoma.

Immune checkpoint inhibitors (ICIs) have recently improved the prognosis of various cancers. By contrast, some immune-related adverse events (irAEs) caused by ICIs are fatal and have become problematic. The pathogenesis of irAEs remains unknown and must be elucidated to establish biomarkers. This study investigated plasma cytokine, chemokine, and anti-CD74 autoantibody levels in patients with renal cell carcinoma (RCC) and analyzed their association with irAEs. In a discovery cohort of 13 patients, plasma levels of chemokine (C-X-C motif) ligand (CXCL) 1, IL-17A, IL-1ß, IL-6, IL-8, CXCL10, MCP-1, and TNFα were measured at baseline and post-dose 1. Only CXCL10, at post-dose 1 but not at baseline, was significantly associated with grade 2 or higher irAEs (P = 0.0413). Plasma CXCL10 levels were then measured at baseline and post-dose 1 in an extended cohort of 43 patients with RCC who received ICI-based treatment. Higher plasma CXCL10 levels both at baseline and post-dose1 were significantly associated with the occurrence of grade 2 or higher irAEs (P = 0.0246 and 0.0137, respectively). Plasma CXCL13 levels, which we measured in a previous study, were significantly higher in patients with grade 2 or higher irAEs at baseline but not at post-dose 1 (P = 0.0037 and 0.052, respectively). No significant association between plasma anti-CD74 autoantibody level and both irAE pneumonitis and any grade 2 or higher irAE was observed. In conclusion, plasma CXCL10 is significantly associated with the occurrence of irAEs in patients with RCC treated with ICIs. CXCL10 is a potential predictive and on-treatment biomarker for irAEs.

Efficacy of avelumab plus axitinib for advanced renal cell carcinoma as late-line therapy: A case report.

A 46-year-old man developed a right renal tumor with multiple lung and hilar lymph node metastases. Laparoscopic radical nephrectomy was performed, and clear cell renal cell carcinoma was diagnosed 6 years earlier. Despite the use of available systemic therapeutic agents, atelectasis in the right upper lobe due to a pulmonary hilar mass and brain metastases reduced his performance, and he was becoming terminally ill. After administration of avelumab plus axitinib as 9th-line therapy, significant shrinkage of the metastases and improvement in performance status were observed. This case indicates the possibility of using avelumab plus axitinib as late-line therapy.

Clear cell carcinoma of the seminal vesicle in a young adult.

Introduction: Most seminal vesicle malignancies are secondary to prostate or bladder cancer. Herein, we report a case of primary clear cell carcinoma of the seminal vesicle. Case presentation: A 27-year-old man was referred to our department for hematospermia and macroscopic hematuria. A digital rectal examination showed a soft elastic prostatic mass. Cystoscopy showed no bladder abnormalities, and tumor marker tests were unremarkable. Contrast-enhanced computed tomography and magnetic resonance imaging revealed a cystic tumor containing an enhanced nodule near the prostate and seminal vesicle. The tumor was removed en bloc with the prostate and seminal vesicle through a laparoscopic radical prostatectomy. A histopathologic examination confirmed the diagnosis, with the tumor likely arising from a remnant Müllerian epithelium. A 1-year follow-up revealed local tumor recurrence, prompting laparoscopy. Conclusion: A standard therapy for primary seminal vesicle carcinoma has not been established. Further studies are necessary to determine the optimal treatment strategy.

Immune-related adverse events in urothelial cancer patients: Adjustment for immortal time bias.

To investigate the association between the onset, severity, and type of immune-related adverse events (irAEs) and the efficacy of pembrolizumab in patients with platinum-pretreated advanced urothelial carcinoma (UC), we retrospectively collected clinical datasets of 755 patients and conducted landmark analysis. Patients who survived for fewer than 3 months were excluded from the evaluation to reduce the immortal time bias. In total, 620 patients were evaluated, of whom 220 patients (35.5%) experienced grade ≥2 irAEs, including 134 patients with grade 2 irAEs and 86 with grade ≥3 irAEs. Propensity score matching extracted 198 patients with and without grade ≥2 irAEs. The onset of grade ≥2 irAEs was associated with longer median progression-free survival (PFS) (8.3 months vs. 4.5 months, p = 0.003) and overall survival (OS) (20.4 months vs. 14.3 months, p = 0.031) and a higher objective response rate (ORR) (44.8% vs. 30.2%, p = 0.004). Patients with grade 2 irAEs had significantly better oncological outcomes (PFS, OS, and ORR) than grade ≤1 and ≥3 irAEs. Patients with grade ≥3 irAEs had worse outcomes than grade 2 irAEs. Endocrine and skin irAEs were related with better survival outcomes, and the rate of severities was lower in these categories. In conclusion, the occurrence of irAEs, particularly low-grade irAEs, was predictive of pembrolizumab efficacy in patients with platinum-pretreated advanced UC.

Subcapsular renal hematoma after ureterorenoscopy.

Introduction: Subcapsular renal hematoma after ureterorenoscopy using a holmium yttrium-aluminum-garnet laser is a rare complication. We experienced a case of subcapsular hematoma after ureterorenoscopy. Case presentation: The patient was a 56-year-old man with a history of hypertension and coronary vasospastic angina, and he was taking antiplatelet drugs. He had the middle and lower calyx stones measured 36 mm in diameter of the right kidney. We performed ureterorenoscopy, which was completed about 2 h without intraoperative complications. We could not remove the stone completely. After the surgery, the patient developed a fever and complained of right back pain. Computed tomography showed several residual stones formed a stone street, obstructing the stent and resulting in grade 3 hydronephrosis. Furthermore, the right subcapsular renal hematoma infection had detected. Percutaneous hematoma drainage and percutaneous nephrostomy were performed. Conclusion: Subcapsular renal hematoma after ureterorenoscopy is an uncommon complication but should be kept in mind.

t(6; 11) renal cell carcinoma. A case report successfully diagnosed by using fluorescence in situ hybridization.

INTRODUCTION: Definitive diagnosis of translocation renal cell carcinoma is challenging. We herein experienced a case of translocation(6;11) renal cell carcinoma, successfully diagnosed by using fluorescence in situ hybridization. CASE PRESENTATION: During the follow-up of a 21-year-old man with Crohn's disease, computed tomography revealed a 40-mm mass in the right kidney. Since imaging could not exclude malignancy, needle biopsy was performed. The histological diagnosis from the biopsy specimen was renal cell carcinoma, but histological typing had not been done adequately. A laparoscopic partial nephrectomy was then performed. Transcription factor EB immunoreactivity was positive, transcription factor EB rearrangement was shown by break apart and fusion fluorescence in situ hybridization. As a result, a definitive diagnosis of t(6; 11) renal cell carcinoma was made. There has been no recurrence for 5 years. CONCLUSION: Transcription factor EB immunohistochemistry and fluorescence in situ hybridization are useful diagnostic tools for renal tumors of young generation.

[Successful Management for Refractory Non-Seminomatous Testicular Cancer with Retroperitoneal Lymph Node, Liver, Lung and Brain Metastases : A Case Report].

An 18-year-old male was aware of painless left testicular enlargement. Contrast-enhanced computed tomography showed a retroperitoneal tumor, multiple liver tumors, and multiple lung tumors. A left testicular tumor was suspected, and left inguinal orchiectomy was performed. The pathological diagnosis was choriocarcinoma, yolk sac tumor, and embryonal carcinoma. Although bleomycin, etoposide and cisplatin therapy was performed as first-line chemotherapy and paclitaxel, iphosfamide and cisplatin therapy was performed as second-line chemotherapy, the tumor markers did not become negative. Retroperitoneal lymph node dissection and partial hepatectomy were performed as desperation surgery. However a new brain metastatic lesion appeared; then, radiation therapy (whole brain irradiation, stereotactic radiotherapy) and gemcitabine, oxaliplatin therapy were performed. The tumor marker became negative, and lung metastases were resected followed by right lower lung lobectomy. No recurrence has been observed for one year and six months after the lobectomy.

Impact of the objective response to and number of cycles of platinum-based first-line chemotherapy for metastatic urothelial carcinoma on overall survival of patients treated with pembrolizumab.

OBJECTIVES: To investigate the impact of the number of cycles and objective response to chemotherapy on overall survival in patients with metastatic urothelial carcinoma treated with pembrolizumab. METHODS: This multicenter, retrospective study included 755 patients from 59 institutions with advanced, chemoresistant urothelial carcinoma who received pembrolizumab. The associations of the overall survival with the number of cycles and best objective response were investigated using Cox multiple regression analysis. RESULTS: Overall, 391 patients received standard first-line chemotherapy and pembrolizumab as a second-line treatment, and were included in the final analysis. Of the 391 patients, 185 received less than four cycles, 134 received four to six cycles and 72 received more than six cycles of first-line chemotherapy. An objective response (complete or partial response) to chemotherapy was observed in 145 patients (37.1%). Univariate analysis showed that the overall survival of patients who received more than six cycles or responded to chemotherapy (complete or partial response) was significantly longer than that of patients who received less than four cycles or did not respond to chemotherapy (stable or progressive disease). At multivariate levels, no correlations were observed between overall survival and the number of cycles of or the response to chemotherapy. CONCLUSIONS: Therapeutic benefit of pembrolizumab can be expected irrespective of the objective response to and number of cycles of platinum-based first-line chemotherapy.

Clinical Impact of Detecting Low-Frequency Variants in Cell-Free DNA on Treatment of Castration-Resistant Prostate Cancer.

PURPOSE: Although cell-free DNA (cfDNA) testing is expected to drive cancer precision medicine, little is known about the significance of detecting low-frequency variants in circulating cell-free tumor DNA (ctDNA) in castration-resistant prostate cancer (CRPC). We aimed to identify genomic profile including low-frequency variants in ctDNA from patients with CRPC and investigate the clinical utility of detecting variants with variant allele frequency (VAF) below 1%. EXPERIMENTAL DESIGN: This prospective, multicenter cohort study enrolled patients with CRPC eligible for treatment with abiraterone or enzalutamide. We performed targeted sequencing of pretreatment cfDNA and paired leukocyte DNA with molecular barcodes, and ctDNA variants with a VAF ≥0.1% were detected using an in-house pipeline. We investigated progression-free survival (PFS) and overall survival (OS) after different ctDNA fraction cutoffs were applied. RESULTS: One hundred patients were analyzed (median follow-up 10.7 months). We detected deleterious ATM, BRCA2, and TP53 variants even in samples with ctDNA fraction below 2%. When the ctDNA fraction cutoff value of 0.4% was applied, significant differences in PFS and OS were found between patients with and without defects in ATM or BRCA2 [HR, 2.52; 95% confidence interval (CI), 1.24-5.11; P = 0.0091] and TP53 (HR, 3.74; 95% CI, 1.60-8.71; P = 0.0014). However, these differences were no longer observed when the ctDNA fraction cutoff value of 2% was applied, and approximately 50% of the samples were classified as ctDNA unquantifiable. CONCLUSIONS: Detecting low-frequency ctDNA variants with a VAF <1% is important to identify clinically informative genomic alterations in CRPC.

High T-cell infiltration in tumor tissue and younger age predict the response to pembrolizumab in recurrent urothelial cancer.

Targeting the programmed cell death-1 signaling pathway has been approved for the anti-cancer therapy in several cancers including urothelial cancer. To determine predictive factors of the responsiveness to pembrolizumab in urothelial cancer patients, a retrospective study that used clinical information and paraffin-embedded samples obtained from patients diagnosed with urothelial cancer between 2015 and 2020 were performed. Seventeen patients who underwent total cystectomy or nephroureterectomy of the primary lesion and were treated with pembrolizumab for chemo-resistant disease were enrolled, and immunohistochemical analysis was performed. A key difference in the characteristics between the non-responder group and the responder group was the age of the patients (74 vs. 63 years, p = 0.0194). Although there was no statistically significant difference, the histological subtype with sarcomatoid and micropapillary components was only seen in the non-responder group, and squamous differentiation and lymph node metastasis were only seen in cases with a complete response. In the results of immunohistochemistry, the density of CD8-positive T-cells and Tregs was significantly increased in the responder group than in the non-responder group. In conclusion, younger age and a high number of tumor-infiltrating lymphocytes were predictive factors of a good response to immune checkpoint inhibitors, although further studies with more enrolled patients are necessary.

Pembrolizumab for treating advanced urothelial carcinoma in patients with impaired performance status: Analysis of a Japanese nationwide cohort.

BACKGROUND: The benefits of pembrolizumab in patients with advanced urothelial carcinoma (UC) and impaired performance status (PS) remain unknown. This study assessed the safety and efficacy of pembrolizumab in patients with platinum-refractory UC and Eastern Cooperative Oncology Group PS ≥2 to identify which subgroups may benefit from this drug. METHODS: This retrospective nationwide cohort study collected clinicopathological information for 755 patients from 59 institutions. The overall response rate (ORR) and overall survival (OS) were compared among the patients with PS 0-1, 2, and 3-4. Multivariate analysis was conducted to identify factors predicting OS in patients with PS ≥2. RESULTS: The numbers of patients with PS 0-1, 2, and 3-4 were 602, 98, and 55, respectively; the ORRs in these groups were 29.5, 15.3, and 9.1%, respectively, and the median OS times were 14.3, 3.1, and 2.4 months, respectively. In multivariate Cox regression analysis, a neutrophil-lymphocyte ratio (NLR) ≥3.5 (hazard ratio [HR] = 1.897) and liver metastasis (HR = 2.072) were associated with OS in the PS ≥2 subgroup. The median OS of patients with PS ≥2 without either risk factor was 6.8 months, compared with 3.1 months for patients with one risk factor and 2.3 months for patients with both risk factors. CONCLUSIONS: PS ≥2 portended worse ORR and OS than PS ≤1 despite a comparable safety profile. Among the patients with impaired PS, patients with NLR <3.5 and no liver metastasis may most greatly benefit from pembrolizumab therapy.

Remarkable antitumor effect of nivolumab in a patient with metastatic renal cell carcinoma previously treated with a peptide-based vaccine.

INTRODUCTION: The safety and efficacy of combination therapy comprising immune checkpoint inhibitors and cancer-specific peptide vaccines have not yet been established. CASE PRESENTATION: A 71-year-old female metastatic renal cell carcinoma patient with multiple lung and pleural metastases. She had been treated with interferon alpha, sunitinib, axitinib, and pazopanib sequentially, but no clinical efficacy was observed. She participated in a clinical trial using cancer-specific peptide vaccine therapy. Initially no antitumor effect was observed, and vaccine therapy was ceased after two courses. But 3 months after the start of nivolumab, remarkable tumor shrinkage was observed at all metastatic sites, which resulted in almost complete response at 6 months. At 10 months, nivolumab was stopped due to cellulitis at the peptide vaccine inoculation site. Intriguingly, even after nivolumab discontinuation, complete response was maintained for more than 1 year. CONCLUSION: We experienced a remarkable antitumor effect by nivolumab in a patient who was previously treated with vaccine therapy.

Dual functions of angiopoietin-like protein 2 signaling in tumor progression and anti-tumor immunity.

Angiopoietin-like protein 2 (ANGPTL2) is a secreted glycoprotein homologous to angiopoietins. Previous studies suggest that tumor cell-derived ANGPTL2 has tumor-promoting function. Here, we conducted mechanistic analysis comparing ANGPTL2 function in cancer progression in a murine syngeneic model of melanoma and a mouse model of translocation renal cell carcinoma (tRCC). ANGPTL2 deficiency in tumor cells slowed tRCC progression, supporting a tumor-promoting role. However, systemic ablation of ANGPTL2 accelerated tRCC progression, supporting a tumor-suppressing role. The syngeneic model also demonstrated a tumor-suppressing role of ANGPTL2 in host tumor microenvironmental cells. Furthermore, the syngeneic model showed that PDGFRα+ fibroblasts in the tumor microenvironment express abundant ANGPTL2 and contribute to tumor suppression. Moreover, host ANGPTL2 facilitates CD8+ T-cell cross-priming and enhances anti-tumor immune responses. Importantly, ANGPTL2 activates dendritic cells through PIR-B-NOTCH signaling and enhances tumor vaccine efficacy. Our study provides strong evidence that ANGPTL2 can function in either tumor promotion or suppression, depending on what cell type it is expressed in.

TFE3 Xp11.2 Translocation Renal Cell Carcinoma Mouse Model Reveals Novel Therapeutic Targets and Identifies GPNMB as a Diagnostic Marker for Human Disease.

Renal cell carcinoma (RCC) associated with Xp11.2 translocation (TFE3-RCC) has been recently defined as a distinct subset of RCC classified by characteristic morphology and clinical presentation. The Xp11 translocations involve the TFE3 transcription factor and produce chimeric TFE3 proteins retaining the basic helix-loop-helix leucine zipper structure for dimerization and DNA binding suggesting that chimeric TFE3 proteins function as oncogenic transcription factors. Diagnostic biomarkers and effective forms of therapy for advanced cases of TFE3-RCC are as yet unavailable. To facilitate the development of molecular based diagnostic tools and targeted therapies for this aggressive kidney cancer, we generated a translocation RCC mouse model, in which the PRCC-TFE3 transgene is expressed specifically in kidneys leading to the development of RCC with characteristic histology. Expression of the receptor tyrosine kinase Ret was elevated in the kidneys of the TFE3-RCC mice, and treatment with RET inhibitor, vandetanib, significantly suppressed RCC growth. Moreover, we found that Gpnmb (Glycoprotein nonmetastatic B) expression was notably elevated in the TFE3-RCC mouse kidneys as seen in human TFE3-RCC tumors, and confirmed that GPNMB is the direct transcriptional target of TFE3 fusions. While GPNMB IHC staining was positive in 9/9 cases of TFE3-RCC, Cathepsin K, a conventional marker for TFE3-RCC, was positive in only 67% of cases. These data support RET as a potential target and GPNMB as a diagnostic marker for TFE3-RCC. The TFE3-RCC mouse provides a preclinical in vivo model for the development of new biomarkers and targeted therapeutics for patients affected with this aggressive form of RCC. IMPLICATIONS: Key findings from studies with this preclinical mouse model of TFE3-RCC underscore the potential for RET as a therapeutic target for treatment of patients with TFE3-RCC, and suggest that GPNMB may serve as diagnostic biomarker for TFE3 fusion RCC.

MicroRNA-204-5p: A novel candidate urinary biomarker of Xp11.2 translocation renal cell carcinoma.

Xp11.2 translocation renal cell carcinoma (Xp11 tRCC) is a rare sporadic pediatric kidney cancer caused by constitutively active TFE3 fusion proteins. Tumors in patients with Xp11 tRCC tend to recur and undergo frequent metastasis, in part due to lack of methods available to detect early-stage disease. Here we generated transgenic (Tg) mice overexpressing the human PRCC-TFE3 fusion gene in renal tubular epithelial cells, as an Xp11 tRCC mouse model. At 20 weeks of age, mice showed no histological abnormalities in kidney but by 40 weeks showed Xp11 tRCC development and related morphological and histological changes. MicroRNA (miR)-204-5p levels in urinary exosomes of 40-week-old Tg mice showing tRCC were significantly elevated compared with levels in control mice. MicroRNA-204-5p expression also significantly increased in primary renal cell carcinoma cell lines established both from Tg mouse tumors and from tumor tissue from 2 Xp11 tRCC patients. All of these lines secreted miR-204-5p-containing exosomes. Notably, we also observed increased miR-204-5p levels in urinary exosomes in 20-week-old renal PRCC-TFE3 Tg mice prior to tRCC development, and those levels were equivalent to those in 40-week-old Tg mice, suggesting that miR-204-5p increases follow expression of constitutively active TFE3 fusion proteins in renal tubular epithelial cells prior to overt tRCC development. Finally, we confirmed that miR-204-5p expression significantly increases in noncancerous human kidney cells after overexpression of a PRCC-TFE3 fusion gene. These findings suggest that miR-204-5p in urinary exosomes could be a useful biomarker for early diagnosis of patients with Xp11 tRCC.

TET2-dependent IL-6 induction mediated by the tumor microenvironment promotes tumor metastasis in osteosarcoma.

The tumor microenvironment promotes epigenetic changes in tumor cells associated with tumor aggressiveness. Here we report that in primary tumor cells, increased interleukin-6 (IL-6) expression brought on by DNA demethylation of its promoter by ten-eleven translocation 2 (TET2) promotes lung metastasis in osteosarcoma (OS). Xenograft experiments show increased IL-6 expression and decreased methylation of its promoter in OS cells after implantation relative to before implantation. In addition, changes in IL-6 methylation and expression seen in OS cells at the primary site were maintained at the metastatic site. TET2 knockdown in OS cells suppressed upregulation of IL-6 and demethylation of its promoter in xenograft tumors and decreased tumor metastasis. We also present evidence showing that tumor cell-derived IL-6 facilitates glycolytic metabolism in tumor cells by activating the MEK/ERK1/2/hypoxia-inducible transcription factor-1α (HIF-1α) pathway and increases lung colonization by OS cells by upregulating expression of intercellular adhesion molecule-1 (ICAM-1), enhancing tumor metastasis. Blocking IL-6 signaling with a humanized monoclonal antibody against the IL-6 receptor reduced lung metastasis and prolonged survival of xenografted mice. These findings suggest that TET2-dependent IL-6 induction enables acquisition of aggressive phenotypes in OS cells via the tumor microenvironment and that blocking IL-6 signaling could be serve as a potential therapy to antagonize metastasis.